Scaffold hoist



Sept; 29, 1925. 1,555,241

w. c. FERRIS SCAFFOLD H-OIST Filed April 7; 1925 s Sheets-Sheet 1 i5 W. C Ferris INVENTOR.

ATTORNEY;

Sept; 29, 1925. g I 1,555,241

w. c. FERRIS SCAFROLD uoxsr Filed April 7, 1925 s Sheets-Sheet 2 7 W. C. Ferris, INVENTOR.

ATTORNEY Sept. 29, 1925. 4 1,555,241v

W. C.'FERRIS SCAFFOLD HOISI F1195 April '7, 1925 5 Sheets-Sheet 5 ATTORNEY,

BY I I Patented Sept. 29, 1925.

UNITED STATES WALTON c. reams, or LINCOLN, NEBRASKA.

SCAFFOLD Horsr.

Application filed April 7, 1925.

T 0 all whom it may con ern...

Be it known that I, Wanton C. Finnnis, a citizen of the United States, residing at Lincoln, in the county of Lancaster and State of Nebraska, have invented certain new and useful Improvements in Sca'lfold Hoists, of which the following is a specification.

My invention relates to scaffold hoists, and more particularly to the supports and to the carriages for climbing the supports.

At the present time, all other scaffolding machines use a long cable, or pipe or wood uprights for supports. The cable is objectionable because it is hard to handle and because it deteriorates rapidly when it repeatedly coiled and uncoiled. During the coiling and uncoiling of the cable the paint is cracked off, and since the strands are usually of small diameter and easily broken, the cable soon becomes frayed and kinked. The uprights made of iron pipe or of wood are also open to serious objections. With either pipe or wood uprights a large amount of material must be used which becomes worthless after very little use. Because of the wastage connected with the use of pipe or wood uprights, the cable has come into probably more extensive use than any of the other types of supports, despite the generally unsatisfactory character of cable when used for this purpose.

In the use of cable supports the carriages climb either by winding the cable on the drum or by means of friction elements en.- gaging the cable. The drum, however. must be large enough to wind up a hundred feet of cable and it therefore has the serious disadvantage of heavy weight, both in the drum itself and in the added reinforcement of the carriage. In starting, the drum has a small sheave diameter which increases toward the end of the hoisting operation as the several layers are wound on the drum. The cable is also apt to pile up high on one side of the sheave, which often makes it a difficult matter to maintain the carriage in a level position. There is also an element of danger when the cable piles up high at one side of the sheave since it is apt to settle down suddenly and to release enough length .of cable to seriously alarm the workmen, to spill bricks from the platform, and to subject the cable and con nections to dangerous strains.

invention has for its object, in brief,

Serial No. 21,332.

the provision of a support which is without the objectionable features of cable, wood, or pipe supports, and the further provision of a light weight carriage which positively engages the support at two points} Refer'ing now to my drawings,

Figure Tie a diagrammatic View in elevation of my scaffold hoist as it appears when secured to a buildingstructure.

Figures 2 and 3 are views of a portion of the jack lift type of carriage and showing also the connections between the carri and the chain support.

Figures l and 5 are similar views of a portion of a modified form of carria e in which the carriage is made to climb by means of a small winding drum. I

Figures 6 and 7 are views of a modified form of chain support.

As a support, I use the chain 10 which is best shown in Figures 2, 3, and 5. I The chain is made up of individual links each having an eye at each extremity, the eyes being either in the same plane as shown in Figure 5 or in planes at right angles to each other as shown in Figure 3, or in any other desired relative position. The chains 10 must be sufficiently strong to carry their own weight with the weight .of the carriage and workmen, and with an. ample margin of safety. The links ;of the chain 10 may be made in any suitable length, and while I do not desire to restrict myself to any particular length, I prefer to make them each about three feet long, which length coincides with the raise required in practice by brick layers. As shown in Figure 1, the chains are secured at their upper ends to Outriggers '11 which are clamped to the building structure by means of .U- bolts 12 or other suitable securing means, and they extend practically to the ground or to the ledge of the building structure.

The advantages of my chain for this purpose are obvious. The tensile strength of chain is practically equal to that of a cable having the same weight. It has a Very much lower initial cost and a very much longer life than that of the cable. It pre sents none of the difliculties in handling that the cable does. In folding, the links are folded into parallelism very much in the manner of folding a surveyors chain.

Since no parts ,of the chain are subjected to bending strains, the chain is not inclined to develope the weaknesses usually found n cables after comparatively short use. Both chains and cables are coat d with paint or other preservative covering which soon cracks and chips off from the cable but which remains adhering to the chain be cause the chain is not subjected to bending strains as the cable is. The chain however has certain other great advantages in its relation to the carriage, which advantages will be pointed out in connection with the following description of the carriage.

Referring now to F igurs 2 and 3, the carriage has an angle iron putlog 18 for supporting the planks of the floor let. The body casting of the carriage is shown at and it is provided with ears 16. The vertically movable member 17 is slidably secured in the body member 15 and it has a chain 18 secured thereto at its upper extremity. The upper end of the chain 18 has a hook 19 which is adapted to be sccured in the lower eye member of one of the links of the chain 10. The movable member 17 has ratchet teeth on its opposite edges for engagement with the pawls 20 which are secured to the lever 21 and connected to each other by means of a coil or other ten sion spring 22. The lever 21 is pivotally secured to the body member 15 in such a way that its reciprocal actuation will cause the pawls 20 to alternately engage the teeth on the movable member 17. In order to facilitate actuation of the lever 21 a handle 23 is provided, the handle being so constructed that it may be easily and quickly secured to the lever or detached therefrom. At the lower extremity of the movable 1111'11- ber 17 is a stop 17 for limiting the upward sliding movement of the movable member in the casting 15, the stop 17 in thisinstance being formed by bending the movable member 17 at its lower end.

The movable memb'r 17 is greater in length than one of the links of the chain 10 and it is firmly secured to the chain through the hook 19 and to the carriage through the pawls and ratchets. The carriage also has a direct positive connection with the chain 10 through a pin 24- which passes through the apertures in the cars 16 and through the eye at the lower end of one of the links of the chain 10, as shown in Figure 3. In this position of the carriage the masons lay the brick wall to a convenient height and then elevate the carriage a distance equal to the len th of one link of the chain 10. The carriage is elevated by first easing the tension on the hook 19 and then withdrawing the hook from the eye of the chain 10, the carriage being still firmly held by the pin 24. After the hook 19 has been releas d from engagement with the chain 10, the pawls 20 are released from engagement with the ratchet and the movable member 17 and the chain 18 are then lifted until the hook 19 engages the eye member of the next higher link of the chain 10. The pin 24 is then withdrawn and the carriage is raised by manipulating the lev r 23, after which the pin 24 is again inserted through the apertures in the ears 16 to engage the eye member of the next higher link. Either connection is, however, alone suliicient to safely support the carriage on the chain 10, so that at such times when only a slight raise is required, the pin 2et'may be temporarily dispensed with, the carriage being then supported solely from the hook 19.

It will thus be seen that while the work men are occupying the platform of the carriage, the carriage is positively secured to the chain at two levels except while the carriage is being raised and exopt also in the few instances when an unusually short raise is required. Both connections are of such construction that slippage is absolutely impossible. Breakage of the chain or of the connections is almost impossible under even the most severe conditions of scaffolding operations, but in the very improbable event of the breakage of one connection, the carriage would still be firmly held through the other connection.

In F i gures l and 5 is shown a modification of the carriage, the chain being similar. The frame 25 is formed from a single strip of steel bent into U-shape. At its bottom it supports the putlog 26 on which is supported the plank flooring 27. Ears 28 are riveted or otherwise secured to the frame 25 and these cars are apertured to receive a pin 29 and in engagement with the chain 10 through the lower eye of one of its links. At the upper end of the U-shaped frame there is mounted a narrow drum or sheave having flanges on each of its sides. These flanges are spaced the Width of the chain or cable which is to be wound on the drum. The flange 30 has ratchet teeth on its periphery, as shown in Figure 5, while the flange 31 is provided with sockets entering from its periphery for the reception of a suitable actuating handle 32. The frame 25 also carries a pivoted pawl 33 engaging the ratchet teeth on the periphery of the flange 30. Secured to the sheave or drum is the lower end of a chain 34:, whose upper end is provided with a hook 35 for entering the lower eye member of one of the links of the chain 10. \Vhile the frame 25 is shown somewhat elongated in Figures l and 5 it may be found desirable in actual practice to shorten the frame somewhat, and I do not desire to be limited to the exact or relative dimensions disclosed in my drawings.

The form of carriage shown in Figures 4- and 5 also has a step by step upward movement with the double positive connection to the chain while the carriage and its platform are inoperative position. -VVhen the carriage is to be movedupwardly the tensionon the hook 35 is first released and the hook is withdrawn from its connection with the chain The pawl 33 is then held away from the ratchet and the hook 35 is lifted to engage the eye member of the next higher link of the chain 10. The pin 29 must then be removed so that actuation of the drum will lift the carriage to a point where the cars 28 will be opposite the next higher eye member of the chain 10. As in the Figure 3 construction, the carriage is made doubly secure to the chain 10 and it is only during the lifting operation that one connection alone is relied upon. Likewise, all of the connections are positive so that no slippage can occur.

It is obvious that the chains which are shown in Figures 3 and 5 may be modified in any one of several ways to accomplish the same or similar results. In fact, the chains 10 and 10 shown respectively in Figures 3 and 5 illustrate one of the minor modifications. In the one case the eyes of a link lie in a common plane while in the other case the eyes lie in planes which are at right angles to each other. By way of illustration, one or more radical modifications is shown in Figures 6 and 7. In this form the links 36 are rod like with bolt heads at each of their ends. The links of the pair are connected as shown in Figure 6 by means of an elliptically shaped plate 37 which has two apertures for receiving the links 36. It is only necessary when using a chain of this kind to modify the hook through which the carriage is suspended from the chain. The hook 38 is solid with bifurcations which enable the hook to straddle the links 36.

I am aware that double positive holding connections are old in scaffold hoists, but the prior devices of this kind are all dependent on iron pipe or on wooden scaffolds. Because of the defects inherent in these materials when used for scaffolds on high buildings, such devices have never been put to any but the most limited use. A second great advantage found in my hoist resides in the fact that the weight of the hoisting mechanism has been reduced to a minimum. Whereas the usual cable or chain hoists must be provided with a drum and actuating mechanism of a size and strength to wind up a hundred feet of cable, the drum of my hoist is called upon to wind up only two or three feet of cable or chain. The entire carriage is thus materially lighter than in the prior devices and the manual labor required to lift it is proportionately reduced. I am aware, however, that one of the most widely used and successful hoists has an exceeding- 1y light carriage, but in that hoist the car-- riage climbs by frictionally engaging the cable. Disastrous slippage occurs frequently in the carriage of the hoistreferred to, and the wearing parts are not sufficiently exposed for frequent inspection. In my hoist, on the other hand, all wearing parts are-exposed at all times so that if any of them get out of order, the fact will be instantly discovered. But even in the almost impossible event that breakage occurs, the slippage of the carriage and platform can have a. maximum range of about three feet and it is likely to be very much less.

Having thus described my inventionin terms which will be readily understood by others skilled in the art to which it pertains, what I claim as new and desire to secure by Letters Patent of the United States is 1. In a scaffold hoist, a supporting chain comprising rod like links connected end to end, and a platform carriage which is adapted tobe secured to any two contiguous links of said supporting chain at the joints thereof, and means secured to said platform carriage for elevating said platform carriage a distance which is substantially equal to the length of one of the links of said supporting chain.

2. In a scaffold hoist, a supporting chain comprising rod like links connected end to end, a platform carriage which is adapted to be elevated on said supporting chain, said platform carriage having means for securing said platform carriage to two contiguous links of the said supporting chain at the joints thereof and having also means secured thereto for manually elevating said platform carriage through steps which are substantially equal to the length of one of the links .of said supporting chain.

3. In a scaffold hoist, a supporting chain which is adapted to be secured at its upper extremity to an outrigger projecting from a building structure, aplatform carriage which is adapted to be elevated on said supporting chain, said platform carriage having means at its base for rigidly securing said platform carriage to said supporting chain at one of the joints thereof, said securing means being releasable, and a flexible element secured at its lower end to said platform carriage and releasably secured at its upper end to said supporting chain at the joint thereof next above said first mentioned joint.

a. In a scaffold hoist, a supporting chain which is adapted to be secured at its upper extremity to an outrigger projecting from a building structure, said supporting chain comprising rod like links which are connected end to end, a platform carriage which is adapted to be elevated on said supporting chain, an apertured ear secured to and projecting from said platform carriage, a pin for releasably securing said ear to the said supporting chain at one of the joints thereof, and a flexible element secured at its lower extremity to said platform carriage and having means at its upper extremity for releasably securing it to said supporting chain at a joint above said first mentioned joint, and means associated with said flexible element for manually elevating said platform carriage with its load When said pin is Withdrawn from said ear.

5. In a scaffold hoist, a supporting chain which is made up of rod like links connected end to end, a platform carriage having a U-shaped frame, a sheave Within said U-shaped frame at the upper extremity thereof, said sheave having the Width of the WALTON C. FERRIS. 

